Pneumatic control system unit and device for receiving the same

ABSTRACT

A housing means having an inlet and outlet separated by valve seat means whereby pneumatically operated valve means carried by the housing means is adapted to open and close the valve seat means. A pneumatically operated control system unit for operating the pneumatically operated valve means is provided in a separate housing unit that is detachably carried by the housing means for the pneumatically operated valve means, the control system unit comprising a plurality of housing plates sonically welded together and retaining pneumatically operated control components for interconnecting a pneumatic source to the pneumatically operated valve means.

United States Patent Inventor Douglas R. Scott Elkhart, Ind.

Appl. No. 58,368

Filed July 27, 1970 Patented Jan. 11, 1972 Assignee Robertshaw ControlsCompany Richmond, Va.

PNEUMATIC CONTROL SYSTEM UNIT AND DEVICE FOR RECEIVING THE SAME 40Claims, 10 Drawing Figs.

US. Cl 137/613, 251/28, ZOO/61.86 Int. Cl ..Fl6k 17/10, F16]: 31/12,HOlh 29/28 Field of Search 200/6 l .86;

References Cited UNITED STATES PATENTS 3,508,850 4/l 970 Good PrimaryExaminer-Henry T. Klinksiek Attorneys-Auzville Jackson, Jr., Robert L.Marben and Candor, Candor and Tassone ABSTRACT: A housing means havingan inlet and outlet separated by valve seat means whereby pneumaticallyoperated valve means carried by the housing means is adapted to open andclose the valve seat means. A pneumatically operated control system unitfor operating the pneumatically operated valve means is provided in aseparate housing unit that is detachably carried by the housing meansfor the pneumatically operated valve means, the control system unitcomprising a'plurality of housing plates sonically welded together andretaining pneumatically operated control components for interconnectinga pneumatic source to the pneumatically operated valve means.

PATENTED m1 1 1972 31633520 snm 1 or 5 INVENTOR. L DOUGLAS R. SCOTT FIG.I BY duh, dua- 7 744m HIS ATTORNEYS PATENIED JMH 1 m2 3533.820

SHEET 3 BF 5 FIG.4

INVENTOR. DOUGLAS R. SCOTT BY 200 5%, 4% 77M 38 HIS ATTORNEYS PATENTEUJAN! 1 I972 Sum u 0E5 INVENTOR. DOUGLAS R. SCOTT HIS ATTORNEYS PNEUMATICoNr oI. SYSTEM UNIT AND DEVICE FOR RECEIVING THE SAME This applicationis related to Ser. No. 5,709, filed Jan. 26, 1970, and concurrentlyfiled patent application Ser. No. 58,284, which respectively discloseand claim a pneumatic control system for a fuel-burning apparatus andthe unique pneumatically operated valve means for the main burner ofsuch anapparatus.

This application relates to such a pneumatic control systemandp'neumatically operated valve means.

In particular, onefeature of this invention is to package at least partof the pneumatic control system into a control system unit anddetachable secure such control system unit to the housing meanscontaining the pneumatically operated valve means for the main burnermeans of the fuel burning apparatus or the like whereby not only is acompact arrangement provided by the features of this invention, but alsorepair and/or replacement parts and costs are minimized because ofdefective control system'unit can be detached from its receiving housingmeans and a new one be placed therein in a simple and effective manner.7

One embodiment of this invention for providing such features comprises acontrol system having a source of fuel, a burner means, a pneumaticsource and a housing means having an inlet interconnected to the fuelsource and an outlet interconnected to the burner means with the inletand outlet being separated by valve seat means adapted to be opened andclosed by pneumatically operated valve means altered by the housingmeans. A pneumatically operated contrel system unit for operating thepneumatically operated valve means is detachably carried by the housingmeans and is adapted to interconnect the pneumatic source to thepneumatically operated valve means to open the same. The pneumaticallyoperated control system unit comprises a plurality of housing platessonically welded together and holding pneumatically operated controlcomponents between such plates. Accordingly, it is an object of thisinvention to provide an improved pneumatic control system having one ormore of the novel features set forth above or hereinafter shown ordescribed.

Another object of this invention is to provide an improved compactarrangement for such a control system or the like.

Another object of this invention is to provide improved means forpackaging such a control system or the like.

Other objects, uses and advantages of this invention are apparent from areading of this description which proceeds with reference to theaccompanying drawings forming a part thereof and wherein:

FIG. 1 is a schematic view illustrating the improved control system ofthis invention.

FIG. 2 is anenlarged, fragmentary view of the pneumatically operatedlogic units of the control system of FIG. 1 with the logic units beingillustrated in cross section.

FIG. 3 is a top view of the pneumatically operated valve means housingand packaged control system unit of this invention.

FIG. 4 is an enlarged cross-sectional view taken on line 44 of FIG. 3.

FIG. 5 is a side view of the structure illustrated in FIG. 3.

FIG. 6 is an exploded perspective view of certain of the parts of thestructure in FIG. 3.

FIG. 7 is a side perspective view of the control system unit of thisinvention. 7

FIG. 8 is a side view ofthe unit of FIG. 7.

FIG. 9 is an enlarged cross-sectional view taken substantially on line9-9 of FIG. 8.

FIG. '10 is an enlarged, partial cross-sectional view taken on line10-10 ofFIG. 8.

While the various features of this invention are hereinafter describedand illustrated as being particularly adapted for providing controlmeans for a fuel-burning clothes dryer, it is to be understood that thevarious features of this invention can be utilized singly or in anycombination thereof to provide control means for other apparatus asdesired.

Therefore, this invention is" not to be limited to only the embodimentillustrated in the drawings, because the'draviihgs are merely utilizedto illustrate one of the wide variety of uses of this invention. I V

In order to more fully understand the packaging features of thisinvention, the overall control system will now he described.

Referring now to FIG. 1, the improved control system of this inventionis generally indicated by the'reference numeral 10 and is utilized forcontrolling the operation of a clothes dryer, generally indicated by thereference numeral 11', having a main burner means 12 adapted to beinterconnected to a fuel source manifold 13 by a pair of pneumaticallyoperated valve means 14 and 14' in'a manner hereinafter'described.

The apparatus 11 includes an' electric motor 15 which rotates theclothes-receiving drum' (not' shown) of the apparatus 11 during theentire cycle of operation of the apparatus 11 in a conventional manner,the electric motor 15 being adapted to be interconnected a'crosstwo'source leads I. and I. in a manner hereinafter described.

The electric motor 15 isadapted to drive an eccentric cam 16 that isinterconnected to its output shaft 17 as long as the electric motor 15is energized whereby the eccentric cam' 16 will continuously move apiston rod arrangement to operate a vacuum pump means 19 so as toprovide a continuous vacuum source for the system 10 of this inventionas long as the electric motor 15 is energized, the vacuumpu'r'np'rnea'ns 19 having its inlet 20 interconnected to a conduit means211.

The power source lead L is interconnected to one side 22 of the electricmotor 15 by a lead 23. The other power source lead L is interconnectedby a lead 24 to a conventional timer operated switch blade 25 that hasits Contact 26 cooperable with a fixed contact 27 that is interconnectedby a lead 28 to a dryer door operated switch blade 29. The dryerdooroperated switch blade 29 has a contact 30 cooperable with-a contact 31that is interconnected by a lead 32 to the other side 33 of the electricmotor 15.

Therefore, it can be seen that in order for the electric motor 15 to beplaced across the powerso'urce leads L and I. for the electric motor 15to be energized, not only must the dryer door be disposed in its closedposition to close and hold the switch blade 29 against the contact 31,but also the housewife or the like must manually set the cycle timermeans (not shown) of the control system 10 so that the same is in an oncondition to hold the switch blade 25 against the contact 27 for apreset time period after the lapse of which the timer cycle means willautomatically open the switch, blade 25 away from the contact 27 toterminate the operation of the control system 10 in a conventionalmanner.

The pneumatically operated valve means 14 and 14 for interconnecting thefuel source conduit 13 to the main burner means 12 of the apparatus 11are substantially identical in construction and operation and while onesuch valve means could properly control the on-off condition of the'mainburner means 12, the use of two such valve means merely provides asafety factor so that if one of the valve means fails, the other valvemeans will still perform its function.

As illustrated in FIG. 1, the pneumatically operated valve means 14 and14' comprise a housing means 35 having valve seats 36 and 36' thatinterconnect a fuel source inlet 37 to a fuel source outlet 38, thevalve seats 36 and 36 being opened and closed by valve members 39 and 39that are moved between their opened and closed positions by vacuumoperated actuators that are generally indicated by the referencenumerals 40 and 40'. The vacuum operated actuators 40 and 40' areschematically illustrated in FIGS. 1 and'2 and thereby comprisecup-shaped housing members 41 and 41' having their open ends 42 and 42closed by flexible diaphragms 43 and 43' that are interconnected to thevalve members 39 and 39' by tying means 44 and 44 in a conventionalmanner whereby the flexible diaphragms 43 and 43 cooperate with thehousings 41 and 41' to define chambers 45 and 45 therebetween.Compression springs 46 and 46 are disposed in the chambers 45 and 45' totend to normally move the flexible diaphragms 43 and 43 in directions tomaintain the valve members 39 and 39 in their closed positions againstthe valve seats 36 and 36 to prevent any flow of fuel to the main burnermeans 12. However, when the vacuum source 19 is interconnected to thechambers 45 and 45 in a manner hereinafter described to evacuate thechambers 45 and 45', the pressure differential acting across thediaphragms 43 and 43' moves the diaphragms 43 and 43' in opposition tothe force of the compression springs 46 and 46' to move the valvemembers 39 and 39' to their open positions so that the fuel source 13will be interconnected to the main burner means 12 as long as thepneumatically operated actuators 40 and 40 are in their actuatedconditions.

The ignition means for the main burner means 12 comprises an ignitioncoil 47 having one side 48 thereof interconnected by a lead 49 to thelead 24 through a door-operated switch 29', similar to door switch 29,so that the side 48 of the ignition coil 47 is always interconnected tothe power source lead L when the dryer door is closed. The other side 50of the ignition coil 47 is interconnected by a lead 51 to a switch blade52 that has a contact 53 cooperable with a contact 54 that isinterconnected to the power source lead L by a lead 55.

A vacuum-operated actuator 56 controls the switch blade 52 and comprisesa cup-shaped housing 57 having its open end 58 closed by a flexiblediaphragm 59 that is interconnected to the switch blade 52 by a suitabletying means 60, the flexible diaphragm 59 cooperating with the housing57 to define a chamber 61 therebetween that receives a compressionspring 62 that normally tends to urge the flexible diaphragm 59 upwardlyto hold the switch blade 52 out of contact with the contact 54 andthereby maintain the ignition coil 47 in its deenergized condition.However, when the chamber 61 of the actuator 56 is interconnected to thevacuum source 19 in a manner hereinafter described, the resultingpressure diflerential acting across the diaphragm 59 moves the diaphragm59 downwardly in opposition to the force of the compression spring 62 toplace the switch blade 52 into contact with the contact 54 so as toplace the ignition coil 47 across source leads L and L When the ignitioncoil 47 is placed across the power source leads I. and 1.. by thevacuum-operated actuator 56 in a manner hereinafter described, theignition coil 47 substantially heats up to a temperature that will besufficient for igniting fuel issuing from the main burner means 12 in aconventional igniting manner.

An ignition coil temperature-sensing means 63 is provided for the systemand comprises a bimetal member 64 that is interconnected to a valvemember 65 by a tying means 66, the valve member 65 being disposed in ahousing means 67 having a valve seat 68 fluidly interconnecting aconduit 69 to a conduit 70. When the bimetal member 64 senses atemperature of the ignition coil 47 below a temperature sufficient forigniting fuel issuing from the main burner means 12, the bimetal member64 is in such a condition that the same maintains the valve member 65away from the valve seat 68 and against a valve seat 68' that leads tothe atmosphere so as to fluidly interconnect the conduits 69 and 70together. However, when the ignition coil 47 reaches an ignitiontemperature the bimetal member 64 warps in such a manner that the samemoves the valve member 65 against the valve seat 68 to terminate thefluid connection between the conduits 69 and 70 and opens the valve seat68 so that atmosphere is interconnected to the conduit 70 for a purposehereinafter described. In addition, when the main burner means 12 isoperating, the bimetal member 64 also senses the flames at the mainburner means 12 so that the bimetal member 64 will maintain the valvemember 65 in its closed position against the valve seat 68 as long asfuel is burning at the main burner means 12.

Another temperature-sensing device 71 is provided for the control system10 and is adapted to sense the temperature effect of the main burnermeans 12. The temperature-sensing means 71 comprises a bimetal member 72that is interconnected to a valve member 73 by a tying means 74, thevalve member 73 being disposed in a housing means 75 to open and close avalve seat 76 thereof that is adapted to fluidly interconnect theatmosphere with the interior of the housing 75 when the valve seat 76 isopen. However, when the valve seat 76 is closed, the housing 75, ineffect, interconnects the conduit 21 to the conduit 69 of the ignitiontemperature sensing means 63.

As long as the temperature effect of the burner means 12 of theapparatus 11 is below a predetermined temperature effect setting of thesensing means 71, the bimetal member 72 maintains the valve member 73against the valve seat 76 to, in effect, fluidly interconnect theconduits 21 and 69 together whereby if the electric motor 15 isenergized, the vacuum source 19 will be interconnected to the conduit69. However, when the temperature-sensing means 71 senses a temperatureeffect of the burner means 12 above the set temperature effect settingof the thermostatic means 71, the bimetal member 72 warps in a manner tomove the valve member 73 away from the valve seat 76 and, thus, ineffect, disconnects the vacuum source 19 from the conduit 69 as theatmosphere is now interconnected to the conduit 69 through the openedvalve seat 76 for a purpose hereinafter described. Of course, it is tobe understood that the sensing device 71 could be manually adjustablefor temperature selection purposes by the housewife or the like or couldbe factory set for an optimum drying temperature for the apparatus 11.

The conduit 69 is interconnected by a conduit 77 to a port means 78 of apneumatically operated logic memory unit 79 later to be described, theconduit 77 also being fluidly interconnected to a conduit 80 that leadsto a port means 81 of a pneumatically operated logic NAND" unit 82 ofthis invention. The conduit 80 has a restriction 83 therein intermediatethe port means 81 of the logic NAND unit 82 and the conduit 77.

The conduit 70 leading from the ignition temperaturesensing means 63 isinterconnected to another port means 85 of the logic NAND unit 82 aswell as to a conduit 86 that is interconnected to one side 87 of a checkvalve 88, the conduit 70 having a restriction means 89 therein inadvance of the conduit 86.

The check valve 88 comprises a housing means 90 having a valve seat 91adapted to be opened and closed by a valve member 92, the valve seat 91being adapted to interconnect the conduit 86 at the side 87 thereof tothe other side 93 of the check valve 88 that leads to a conduit 94. Thevalve member 92 normally seats against the valve seat 91 to preventfluid communication between the conduits 86 and 94 so that when theconduit 70 is interconnected to the vacuum source 19 by the valve means63 and 71 being disposed in the positions of FIG. 1, the vacuum source19 opens the valve member 92 away from the valve seat 91 so as to beinterconnected to the conduit 94.

The conduit 94 is fluidly interconnected to a conduit 95 that has oneend 96 thereof interconnected to a port means 97 of the logic memoryunit 79 while the other end 98 of the conduit 95 is interconnected toanother port means 99 of the logic memory unit 79.

The conduit 95 is fluidly interconnected to a conduit 101 that leads toa port means 102 of the logic NAND" unit 82, the logic NAND unit havinganother port means 103 thereof fluidly interconnected to a conduit means104 that is fluidly interconnected to branch conduit means 105 and 105'that are respectively fluidly interconnected to the chambers 45 and 45of the vacuum actuators 40 and 40'. The branch conduits 105 and 105respectively have restrictions 107 and 107' therein.

The conduit 104 intermediate the actuators 40 and 40' and the NAND" unit82 is interconnected to the atmosphere by a controlled bleed means for apurpose hereinafter described. However, the controlled bleed means 100interconnects the conduit 104 to the atmosphere at a controlled ratethat is less than the effective rate of fluid interconnection providedby the restriction 83 in the conduit 77 as will be apparent hereinafter.

rmediatetherestriction 89 and the sensor 63 for purpose hereinafterdescribed and to the atmosphere through a restriction100', the conduit110 having a one-way check valve 88 similar to the check valve 88whereby like parts are indicated bylike reference numerals followed by aprime mark.

As previously stated, the control system is so constructed and arrangedthat the ignition coil 47 for the burner means 12 1 must be firstenergized to a temperature thereof that will be sufficient for ignitingfuel issuing from the burner, means 12 each time before the actuators 40and 40 will be actuated to simultaneously move the valve members 39 and39' from their closed positions to their, open positions to cause fuelto issue from the main burner means 12.

Thus, since both temperature-sensing devices 63 and 71 are normallydisposed in the positions illustrated in FIG. 1 when the control system10is initially turned on by the housewife or the like setting the timercycle means in its on" position to close the switch blade 25 against thecontact 27 ,,the thus energized electric motor'15 will operate thevacuum, pump 19 and since the temperature effect of the apparatus 11 isbelow the temperature'effectrsetting of the thermostatic device 71, thevacuum pump 19 is adapted to evacuate the conduit 69 throughthe closedhousing 75 as well as to evacuate the conduit means 70 and 77 leadingrespectively to the logic memory" unit 79 and logic NAND unit 82.

The logic NAND unit 82 will now receive a pneumatic signal at the portmeans 102 thereof from the memory" unit 79 as well as a pneumatic signalat the port means 85 thereof as long as the valve member65 of theignition temperaturesensing means 63 is in its open position from thevalve seat 68 and is closedoagainstthe valve seat 68 whereby the NANDunit will be in a deactivated condition to prevent the vacuum source-19from being interconnected to the conduit 104 so that the valve means 14and 14' remain in their closed positions to prevent fuel from reachingthe main burner means 12.

' However, after the ignition coil47 reaches its ignition condition, thevalve means 65 closes against the valve seat 68 and opens the valve seat68' so as to terminate the pneumatic signal to the port means 85 of theNAND unit 82 whereby the NAND" unit 82 will now be activated to acondition thereof to interconnect the vacuum source19 to the conduit 104so that the actuators 40 and 40' will be evacuated to open the valvemembers 39 and-39 so that fuel can issue from the burner means 12 andbeignited by the ignition means 47.

Accordingly, the logic units 79 and 82 always require that the valvemember 65 must first be in its open position away from the valve seat 68and then be moved to a closed position against the valve seat 68 after.each closing of the main valve means14 and 14' before the main valvemeans 14 and 14 can be again opened, the valve member 65 only closingagainst the valve seat 68 after an open condition thereof by theignition coil 47 being energized to a temperature suitable for ignitingfuel thatis to subsequently issue from the main burner means 12.

The details of the logic units 79 and 82 for accomplishing the abovefunction will now be described in detail whereby 7 reference is, nowmade to FIG. 2.

, letter A." In this manner, it will be appreciated thatthe logic unitsof this invention can be vmade from thesame parts in a simple andefi'ective manner while producing Edifferent logic functions as will beapparent hereinafter so that the cost of the control system l0 of thisinvention is relatively smallwhen considering the costsofpriorknown-electrical and pneumatic control systems.

As illustrated in FIG. 2, the logic memory unit79comprises two housingparts, I 111 and 112 suitably secured together to holdtwoannular'members 113 and'114 between the opposed and respective innerend wall me ans 115;and-1 16 thereof. A flexible, one-piece; diaphragmflmember. 11.7; is disposed in the housing means 111 and 112aridhas anintermediate or large central outwardly directed diaphragm portion 118providedwith anouter peripheral portion 119 that is secured and sealedbetween thevannular members.1l3 and 114. An outboard'smaller spaceddiaphragm portion 120 of, the diaphragm member 117 has its outerperiphery 121 secured and sealed between the housing member 111 and theannular member 113 to define a chamber 122 between the diaphragm portion120 and the end wall means 1150f the housing member 111 whilecooperating with the larger central diaphragm portion 11810 define achamber123 between the diaphragm portions 118 and 120. An opposedsmaller outboard spaced diaphragm portion 124 of the diaphragm member117 has itsouter'periphery 125 secured and sealed between the annularmember 114 and the housing member 112 to define a chamber 126 betweenthe diaphragm portion 124 and the end wall means 116 of the housingmember-112 while cooperating with the central diaphragm portion 118 todefine a chamber 127 between the diaphragm portions 118 and 124. V

The diaphragm member 117has a bore 128interrupting the end 129 thereofso as to receive a compression spring 130 that has one endbearingagainst. the end wall means 116 of the housing member 112 and theother end thereof bearing against the diaphragm member 117 to normallyurge the diaphragm portion 120 against a frustoconical valve seat 131that projects inwardly from the end wall means 115 of the housing member111 intothe chamber-122i The valve seat means 131 of the logic memory"unit 79 is interconnected to the port means 78 thereof that leads to theconduit 77 whereas the valve seat means131A of the NAND" unit 82 isinterconnected to the port means 81 that leads to the conduit 80.

The diaphragm member 117 has a passage means 132 passing through thediaphragm portion 120 inioffset relation to the valve seat 131 so as toalways fluidly interconnect the chambers 122 and 126 together, thepassage 132 also being in offset relation to a frustoconical valveseat133 that projects inwardly from the end wall means 1 15 of thehousing member 112 and is received in the bore 128 of the diaphragmmember 117 to be opened and closed by the end wall .134 ofthe diaphragmmember 117 that defines the closed end'of, the bore 128 and forms partof the effective surface of the diaphragm portion 124 thatcdefinesthechamber 126. .The valve seat 133 of the logic memory" unit 79 isinterconnected to the port 110 which leads to the conduit 110. and thevalve seat 133A of the logic NANDYun it82 is interconnected to the portmeans 108 that leads to the atmosphere.

The port means 78 and 99 of the housing member 111 and the port means110 of the housing member 112 can comprise outwardly extending tubularnipples-that can beeffectively telescoped into flexible conduit means tofluidly interconnect the same to such conduit means, such nippleextensions containing suitable air-filtering means 134. In theembodiment illustrated in FIG. 2, the nipple port means 99 and 78 of,the logic memoryfunit 79 are fluidlyinterconnectedrespectively to theconduits 98 and 70 whereasthe nipple port means 81 and 103 of the logic"NAND? unit 82 arerespectivelyinterconnected to the conduits 80 and 104.

The annular member 114 carries'the port means 97 in the form of a nippleextension projecting out of an opening means 135 in the housing member112 andthe port means.109 com- :prises a nipple extension of the annularmember'11 3 projecting out of an opening means 136 of the housing member11 1. The nipple port means 97 of the logic memory unit 79 isinterconnected to the end 96 of the conduit member 95 and the nippleport means 109 is interconnected to the atmosphere whereas thecorresponding nipple port means 102 and 85 of the logic NAND unit 82 arerespectively interconnected to the conduits 101 and 70.

Accordingly, it can be seen that the chamber 122 of the logic memory"unit 79 is always interconnected to the port means 99 and, thus, to theend 98 of the conduit 95 whereas the port means 78 and, thus, theconduit 77 is adapted to be interconnected to the chamber 122 when thediaphragm member 117 opens the valve seat 131. The atmosphere port means109 is always interconnected to the chamber 123. The chamber 127 isalways interconnected by the port means 97 to the end 96 of the conduitmeans 95. As previously stated, the chamber 126 is always interconnectedto the chamber 122 by the passage means 132 and is adapted to beinterconnected to the atmosphere or effectively blocked from theatmosphere at the port means 110 except for the controlled rate providedby the bleed restriction 100 when the diaphragm member 117 opens thevalve seat 133 depending on whether the valve 88 is open or closed aswill be apparent hereinafter.

ln regard to the logic NAND unit 82, the chamber 122A thereof is alwaysinterconnected by the port means 103 to the conduit 104 and is adaptedto be interconnected to the port means 81 and, thus, to the conduit 80when the diaphragm member 117A opens the valve seat 131A, the chamber122A always being interconnected to the chamber 126A by the passagemeans 132A in the diaphragm member 117A. The chamber 123A is alwaysinterconnected by the port means 85 to the conduit 70. The chamber 127Ais always interconnected by the port means 102 to the conduit 101. Thechamber 126A, while always being interconnected to the chamber 122A bythe passage means 132A in the diaphragm member 117A, is adapted to beinterconnected to the atmosphere at the port 108 when the diaphragmmember 117A opens the valve seat 133A.

The operation of the control system 10 of this invention will now bedescribed.

Assuming that the dryer door is in its closed position to hold theswitch blades 29 and 29 in their closed positions, the housewife or thelike sets the timer selector means for operating the dryer 11 for apredetermined length of time whereby the timer mechanism closes andholds the switch blade 25 against the contact 27 and will maintain theswitch blade 25 against the contact 27 during the entire cycle ofoperation of the dryer 11 so that the conclusion of such time period,the timer means will automatically open the blade 25 away from thecontact 27 to terminate the operation of the apparatus 11.

With the switch blade 25 now moved to its closed position against thecontact 27, it can be seen that the electric motor is placed across thepower source leads L and L so that the electric motor 15 willcontinuously rotate the laundryreceiving drum to tumble the clothes inan atmosphere to be heated by the burner means 12 for drying of thelaundry or the like. As the output shaft 17 of the motor 15 iscontinuously rotating, the same through the eccentric cam 16reciprocates suitable pumping mechanism of the vacuum pump 19 tocontinuously provide a vacuum source for the control system 10.

At the initial operation of the control system 10, not only is theignition coil 47 not at an ignition temperature, but also thetemperature effect of the apparatus 11 is below the temperature effectsetting of the thermostatic means 71 whereby both valve members 65 and73 are in the position as illustrated in FIG. 1 so that the vacuumsource 19 is not only interconnected to the vacuum-operated actuator 56to evacuate the chamber 61 thereof and close the switch blade 52 againstthe contact 54 to place the ignition coil 47 across the power sourceleads L and L but also the vacuum source 19 is interconnected by theconduits 77 and 80 to the valve seats 131 and 131A of the memory" unit79 and NAND" unit 82, which valve seats 131 and 131A are normally closedby the diaphragm members 117 and 117A due to the force of the respectivecompression springs 130 and 130A, and by the conduit means 70 to thechambers 127 and 122 of the memory" unit 79 and the chamber 123A of theNAND" unit 82. The vacuum in the conduits 70 and 110' causes the checkvalve 88 to close so that the open valve seat 133 of the "memory" unit79 is effectively blocked from the atmosphere as the bleed 100' does noteffect evacuation of chamber 126.

In particular, since the conduit 70 is interconnected to the inlet 20 ofthe vacuum pump 19 by the positioned valve members 65 and 73, the vacuumpump 19 can evacuate the chamber 123A or the NAND" unit 82 to maintainthe diaphragm member 117A thereof in its deactivated and seatingposition against the valve seat 131A so that the vacuum source in theconduit leading to the valve seat 131A cannot reach the actuators 40 and40' to open the valve means 14 and 14.

Also, since the conduit 86 is now being evacuated, the check valve 88opens whereas the check valve 88 closes so that the conduit can beevacuated whereby the end 96 thereof evacuates the chamber 127 of thememory" unit 79 so that the resulting pressure differential actingacross the large central diaphragm portion 118 causes the diaphragmmember 117 to move upwardly in FIG. 2 in opposition to the force of thecompression spring in its activated position to I open the valve seat131.

However, before the evacuation of the chamber 127 of the memory unit 79can effect the switching of the diaphragm member 117 upwardly in FIG. 2,the vacuum source 19 now being interconnected to the chamber 126 by wayof conduit 95, chamber 122 and diaphragm passage 132 to chamber 126,assists in the complete evacuation of the chamber 122 so that when thediaphragm member 117 does switch to its up position in FIG. 2, noatmospheric pressure is permitted to pass out into the conduit 95 and,thus, slow down or prevent the setting of the memory" unit 79 in its"on" position.

With the valve seat 131 now being opened by the activated memory" unit79, the vacuum source 19 is interconnected by the conduit 77 through therestriction means 83 to the chamber 122 of the memory" unit 79 so thatthe conduit 101 effectively leading from the chamber 122 of the memoryunit 79 is evacuated to evacuate the chamber 127A of the NAND unit 82.

With the chamber 127A of the NAND unit 82 now being evacuated, it can beseen that as long as the valve member 65 of the ignitiontemperature-sensing means 63 is in its seated position against the valveseat 68', the opposing chamber 123A of the NAND" unit 82 is alsoevacuated so that an equal vacuum condition exists across the centraldiaphragm portion 11 118A of the diaphragm member 117A of the NAND" unit82 so that the compression spring 130A maintains the diaphragm member117A in its up or deactivated position in H6. 2 to maintain the valveseat 131A thereof closed and the chamber 122A thereof that leads to thechambers 45 and 45 of the actuators 40 and 40' of the valve means 14 and14 interconnected to the atmosphere through the passage means 132A ofthe diaphragm member 117A and the open valve seat 133A whereby the valvemembers 14 and 14' cannot be opened to interconnect the fuel source 13to the main burner means 12 as long as a vacuum signal is directed tothe chamber 123A by the ignition-sensing means 63.

However, when the energized ignition coil 47 subsequently heats up toignition condition, the sensing member 64 warps downwardly in FIG. 1 toopen the valve seat 68 and close the valve member 65 against the valveseat 68 thereby disconnect the vacuum source 19 from the conduit 70which begins to return to atmospheric condition by the opened valve seat68 so that not only is the chamber 61 of the actuator 56 returned toatmospheric condition to open the switch blade 52 away from the contact54 and deenergize the ignition coil 47, but also the chamber 123A of theNAND" unit 82 returns to atmospheric condition whereby the resultingpressure differential acting across the diaphragm portion 118A of thediaphragm member 117A of the NAND unit 82 causes the diaphragm member117A to move downwardly in FIG. 2 in opposition to the force of thecompression spring 130A to its activated position to not only open thevalve seat 131A to the chamber 122A, but also to close the valve seat133A from the chamber 126A.

In this manner since the valve member 73 of the temperature effectsensing means 71 in its open condition, the vacuum source 19, in effect,is interconnected to the chambers 45 and 45' of the actuators 40 and 40to move the valve members 39 and 39 to their open positions so that thefuel source 13 is now interconnected to the main burner means 12 and isignited by the ignition coil47.

As previously stated, when the valve member 65 of the ignitiontemperature-sensing means 63 is moved to its closed position against thevalve seat to permit the now opened valve seat 68' to return the conduit70 to atmospheric condition to terminate the vacuum signal to thechamber 123A of the NAND unit 82 so as to activate the same, the checkvalve 88 closes so that such return of air into the conduit 70 cannotreach the conduit 94 whereby the diaphragm member 117 of the memory{unit 79 remains in its actuated condition wherein the valve seat 131 isin its open condition and the valve seat 133 is inits closed conditionso that a continuous vacuum signal is directed from the chamber 122 tothe chamber 127A of the NAND unit to maintain the NAND unit in itsactivated position for maintaining the valve means 14 and 14' in theiropen condition, the restriction-83 providing a greater flow than thecontrolled bleed means 100 in the conduit 104 so that the valve means 14and 14 remain open. A holding circuit is provided for the memory" unitfrom the vacuum source 19 to the chamber 122 of the memory unit 79 andby means of the conduit 95 to the chamber 127 to maintain the diaphragmmember 117 in its up or activated position. Also, the returnvof air intothe conduit 70 causes the check valve 88' to open whereby atmosphere isat the closed valve seat 133 of unit 79.

Thus, since flames now exist at the main burner means 12, thetemperature-sensing means 63 will maintain the valve member65 closedagainst the valve seat 68 so that the burner means 12 will continue tooperate unless the temperature effect being produced by the burner means12 exceeds the predetermined temperature effect setting of thethermostat means 71.

If the temperature effect of the burner means 12 exceeds the setting ofthe thermostat 71, the temperature-sensing member 72 will move the valvemember 73 away from the valve seat 76 to effectively disconnect theconduit 77 from the vacuum source 19 whereby the air will return notonly to the chamber 127 of the memory unit "79 through the opened valveseat 131 to deactivate the same, but also permit air to return to thechamber 127A of the "NAND unit 82 whereby the compression spring 120A ofthe NAND" unit 82 will move the diaphragm member 117A upwardly to closethe valve seat 131A and open the valve seat 133A so that the chambers 45and 45' and the actuators 30 and 30' will be interconnected to theatmosphere by the passage means 132A in the diaphragm member 117Aleading to the chamber 126A that is interconnected to the open valveseat 123A that leads to the atmosphere at the port 108 as well as by thebleed means 100 in the conduit 104. Similarly, the diaphragm member 117of the memory" unit 79 moves downwardly in FIG. 2 under the force of thecompression spring 130 because the chamber 127 returns to atmosphericcondition so that the valve seat 131 is now closed and the valve seat133 is opened to return the chamber 126 to atmospheric condition.

Since flames do not now exist at the main burner means 12, the ignitiontemperature-sensing means 63 now causes the valve member 65 to move awayfrom the valve seat 68 and against the valve seat 68 so that when thevalve member 73 of the thermostat 71 is again moved to its closedcondition against the valve seat 76 by the temperature effect in thedryer 11 falling below the set temperature effect of the thermostat 71,the main burner means 12 will be operated in the manner previouslydescribed wherein the igniter means 47 will again be first energized toignition condition before the valve members 14 and 14' can be opened.

However, if during the normal operation of the control system 10,wherein the main burner means 12 has been interconnected to the fuelsource 13 in the manner previously described so as to be continuouslyburning, the housewife or the like should open the dryer doortemporarily to cause the switch blades 29 and 29' to open so as todisconnect the electric motor 15 from the power source leads L and I.whereby the vacuum source19 ceases to function so that the controlsystem bleeds to atmospheric condition by the controlled bleed 100, andthe housewife subsequently closes the .dryer door to again activate themotor 15 before the ignitiontemperature sensing means 63 has moved thevalve member 65 away from the valve seat 68, the NAND unit 82 cannotcause reopening of the valve means 14 and 14 because the memory" unit 79has not beenreset to its activated position so as to interconnect theconduit 77 to the chamber 122 thereof and, thus, to the chamber 127A ofthe NAND unit 82 as it requires an opening of the valve member 65 awayfrom the valve seat 68 of the ignition temperature-sensing means 63 toactivate the memory unit 79 and the NAND unit 82 requires a subsequentclosing of the valve member 65 against the valve seat 68 to terminatethe vacuum signal to the chamber 123A thereof before the NAND unit82 canbe activated to cause opening of the valve means 14 and 14.

Thus, it can be seen that the control system 10 of this inventionutilizes only two logic units each formed .of identical structure butperforming different logic functions in a manner to control the mainburner means 12 so that the system requires that the ignition means 47be always'pneumatically operated to ignition condition before the mainburner means 12 can be pneumatically operated to its on condition eachtime there is a requirement to turn on the main burner means.

Further, it can be seen that the logic unit79 of this invention is soconstructed and arranged that during the time of switching the memory"unit 79, no atmospheric signal is seen" by the unit 79 to slow down orprevent its switching operation.

Further, any clogging of the restrictions 89 and 83 by .dirt or the likeduring the operation of the system 10 will not cause an adversesituation as the bleed means will cause the valve means 14 and 14 toclose and thereby terminate the operation of the burner 12.

The details of the pneumatically operated valve means 14 and 14 of thisinvention will now be described and reference is now made to FIG. 3wherein it can be seen that the previously described pneumaticallyoperated valve means 14 and 14' are defined by the same housing means 35having the inlet, 37 and outlet 38 formed therein and separated fromeachother by the valve seats 37 and 36' in series with the outlet 38comprising an orifice having a tapering portion 200 and a cylindricalportion 201 to be controlled by the tapering end 202 of a metering pin203 nonnally urged to one flow rate position relative to the orifice 38by a compression spring 204 having one end 205 bearing against ashoulder 206 of the metering pin 203 and the other end 207 bearingagainst a shoulder means 208 of the housing 35.

The previously described valve members 39 and 39, tying means 44 and 44,and flexible diaphragms 43 and 43' are respectively defined by flexiblediaphragms 209 and 209 having their outer peripheries 210 and 210'sealed to annular surfaces 211 and 211 of the housing means 35 by thecup-shaped housing members 41and 41 previously described as the same arefastened to the housing means 35 by suitable fastening means 212 and 212whereby the cup-shaped housing members 41 and 41 cooperate with theflexible diaphragms 209 and 209' to define the previously describedchambers 45 and 45 adapted to be respectively disposed in fluidcommunication with the branch conduits and 105' through-suitable openingmeans in the housing means 35 or cup-shaped housing members 41 and 41'as desired. The diaphragms 209 and 209' respectively have thickenedcentral portions which define valve members 213 and 213 for opening andclosing the valve seats 36 and 36', the compression springs 46 and 46 inthe chambers 45 and 45' respectively tending to maintain the valvemembers 213 and 213 against their respective valve seat 36 and 36'.

The housing means 35 has a stepped cylindrical passage 214 leading tothe valve seat 36 and being transversely intersected by the inlet 37.Fluid flow through the stepped cylindrical passage 214 to the valve seat36 is controlled by a pressure regulator generally indicated by thereference numeral 215 throughout the various figures in the drawings andcan be of any desired type.

However, the particular pressure regulator 215 illustrated in thedrawings is of the type that is fully disclosed and claimed in Ser. No.643,170, filed June 2, 1967, now U.S. Pat. No. 3,550,623, and Ser. No.740,150, filed June 26, 1968, such copending applications being assignedto the same assignee to whom this application is assigned and do notform a part of this invention. Therefore, only sufficient details of thepressure regulator structure 215 will now be described in order to fullyunderstand the features of this invention.

As illustrated in FIG. 3, the housing 35 carries a pair of flexiblediaphragms 216 and 217 respectively having their outer peripheries 218and 219 held in annular grooves 220 and 221 of the housing means 35 bymetallic retainers 222 and 223, the retainer 223 also forming a closuremember. A valve stem 224 has a portion 225 passing through an opening226 in the flexible diaphragm 216 while being coupled thereto by a sealmember 227, the part 225 being interconnected to the medial portion 228of the flexible diaphragm 217 so as to move in unison therewith. Thevalve stem 224 carries a valve member 229 at the lower end thereof forcooperating with a valve seat 230 defined by the stepped portion of thecylindrical passage 214, the valve stem 224 having suitable guide fins231 thereon for guiding movement of the valve stem 224 in thecylindrical passage 214. The valve stem 224 is hollow so as tointerconnect the enlarged part 232 of the passage 214 below the valveseat 230 thereof and above the valve seat 36 to a chamber 233 definedbetween the flexible diaphragms 216 and 217.

The metallic retainer 223 substantially closes off the upper end of thehousing 35 and has a tubular portion 234 being internally threaded at235 to receive a threaded adjusting member 236. A compression spring 237is disposed between the adjusting member 236 and the diaphragm 217 totend to urge the diaphragm 217 and, thus, the valve member 229downwardly in a direction to open the valve seat 230.

In this manner, the setting of the adjusting member 236 and, thus, theforce of the compression spring 237 will cause the pressure regulator215 to maintain the pressure of the fuel passing through the housing 35from the fuel source 13 to the burner means 12 to be maintained at thepressure setting of the device 236 in the manner fully disclosed in theaforementioned copending patent applications relating to the regulator215.

In particular, the pressure of the fuel in the part 232 below the valveseat 230 is conveyed to the chamber 233 between the diaphragms 216 and217 to act against the under side of the diaphragm 217 in opposing theforce of the compression spring 237 tending to move the diaphragm 217downwardly. Thus, when the fuel pressure in the part 232 of the housing35 exceeds the pressure setting, the same moves the diaphragm 217upwardly in opposition to the force of the compression spring 237 todecrease the amount of opening of the valve seat 230 whereby thepressure in the outlet portion 232 of the housing 35 drops accordingly.Conversely, if the fuel pressure in the part 232 of the housing fallsbelowthe pressure setting of the regulator 215, the force of thepressure in the chamber 233 has decreased so that the compression spring237 moves the flexible diaphragm 217 downwardly to increase the amountof opening of the valve seat 230 so that the pressure in the part 232 ofthe housing 35 can be increased.

In order to guide opening and closing movement of the valve members 213and 213' relative to their respective valve seats 36 and 36', the valvemembers 213 and 213 carry guide extensions 238 and 238' that projectthrough the valve seats 36 and 36' so as to guide open and closingmovement of the valve members 213 and 213' without restricting the flowthrough the valve seats 36 and 36'.

The guide member 238 of the valve member 213' carries a lost motionmeans generally indicated by the reference numeral 239 forinterconnecting the valve member 213 to the metering pin 203 so as tocontrol movement thereof when the lost motion means 239 is fully takenup in a manner hereinafter described.

In particular, the lost motion means 239 comprises a substantiallycup-shaped member 240 telescoped over the enlarged upper end 241 of themetering pin 203 so that the under surface 242 of the enlarged head 241of the metering pin 203 is normally spaced above an annular shouldermeans 243 of the cup-shaped member 240 when the valve member 213 isdisposed in its closed position against the valve seat 36' asillustrated in FlG. 3. However, when the chamber 45' is evacuated bybeing interconnected to a vacuum source, the diaphragm 209' is pulledupwardly in opposition to the force of the compression spring 46' andthe valve member 213' opens relative to the valve seat 36 and will notcause movement of the metering pin 203 relative to the orifice 38 untilthe shoulder 243 of the lost motion cup member 240 abuts against theunder surface 242 of the enlarged head 241 of the metering pin 203 tomove the same upwardly relative to the orifice 38 in opposition to theforce of the compression spring 204 whereby when the diaphragm 209' isdisposed in the full up position thereof the metering pin 203 is nowprovided a greater fuel flow rate through the orifice 38 than when inthe non'nal position illustrated in FIG. 3.

Accordingly, upon the opening of the valve member 213, if the same isonly opened relative to the valve seat 36 a distance sufficient toprevent movement of the metering pin 203 from the position illustratedin FIG. 3 to the position illustrated in FIG. 4, the pneumaticallyoperated valve means 14 and 14' of this invention will provide fuel flowto the burner means 12 at the flow rate level provided by the meteringpin 203 in its position as illustrated in FIG. 3. However, if the vacuumlevel being interconnected to the chamber 45' is increased so as tocause the diaphragm 209' to further move upwardly and carry the meteringpin 203 therewith, an increased fuel flow level will be provided by thevalve means 14 and 14' of this invention for the burner means 12.

Accordingly, the branch conduit as illustrated in FIGS. 1 and 2 can havea selector means 244 therein for controlling the degree of vacuum beingdirected to the chamber 45 so that at one setting of the selector 244,the interconnection of the vacuum source to the chamber 45 by thecontrol system 10 in the manner previously described will only cause thediaphragm 209 to move to an intermediate position thereof for openingthe valve seat 36' without causing movement of the metering pin 203 fromthe position illustrated in FIG. 3. The other setting of the selectormeans 244 will permit full vacuum to be interconnected to the chamber 45so that the diaphragm 209' will move to a position for providing a highflow rate to the burner means 12.

However, it is to be understood that the control system 10 of thisinvention can be utilized without the selector means 244 with the lostmotion means 239 either not affecting the metering pin 203 upon theopening of the valve seats 36 and 36' or moving the pin 203 to a newposition thereof where such lost motion means 239 permits relativelylarge movement of the valve member 213' and relatively short movement ofthe pin 203.

In any event, it can be seen that when the control system 10interconnects the vacuum source to the branch conduits 105 and 105' inthe manner previously described, the diaphragms 209 and 209 cause thevalve members 213 and 213' to open away respectively from the valveseats 36 and 36 so that the fuel source 13 can be interconnected to theburner means 12 and can have the pressure thereof regulated by thepressure regulator 215.

The housing means 35 for the pneumatically operated valve means 14 and14' has a side part 250 as illustrated in FIG. 6 that is provided with apocket means or recess 251 of substantially rectangular cross-sectionalconfiguration and defining a flat surface 252 having opening means 253and 254 interrupting the surface 252 and respectively leading to thechambers 45 and 45 for the pneumatically operated valve means 14 and 14.In addition, the surface 252 is interrupted by a cutout or recess 255for a purpose hereinafter described.

A cover member 256 is provided for closing the open side 257 of thepocket means 251, the cover member 256 having inwardly turned sideflanges 258 for telescoping around projections 259 on the housing part250 whereby the cover member 256is adapted to close off the side 257thereof in a manner fully illustrated in FIGS. 3 and 5.

The pocket means 251 of the housing means 35 is adapted to receive acontrol system unit of this invention which is generally indicated bythe reference numeral 260 with the unit 260 having a substantiallyrectangular cross-sectional configuration complementing theconfiguration of the pocket 251 in the manner fully illustrated in FIGS.3 and 5, the unit 260 having outwardly extending conduit nipples 261 and262 projecting from the flat surface 263 thereof in the mannerillustrated in FIG. 7 for respectively telescoping into the openingmeans 253 and 254 of the surface 252 of the housing means 35 when theunit 260 is inserted in the pocket 251 thereof.

The side 264 of the control system unit 260 is interrupted by a valve orrecess 265 that defines a flat surface 266 also having outwardlydirected conduit nipples 267 and 268 for respectively coupling to theconduits 70 and 77 of the system 10 illustrated in FIG. 1. In addition,the pneumatically operated electrical switch means 56 of FIG. 1 isdisposed in a well means 265 of the control system 260 as illustrated inFIG. 6 with the well means 265 being adapted to be completely closed offby the cover means 256 in the manner illustrated in FIG. when thecontrol unit 260 is assembled to the housing means 35.

The control system unit 260 is formed from a plurality of flat housingplates 269 sonically welded together and formed in such a manner thatthe same provide means for holding together the control components 79and 82 as well as the check valves 88 and 88 of the system of FIG. 1together with the interconnecting passages and restrictions disclosed inFIG. 1, such ,control system unit 260 holding the previously describeddiaphragm means or members 117 and 117A and check valve members 92 and92 in the manner fully disclosed and claimed in U.S. Pat. No. 3,433,413,issued Mar. 18, 1969, whereby the details of packaging the logic units79 and 82 as well as the check valve means 88 and 88 and interconnectingpassages into the unit 260 need not be described as the subject matterof such features comprise the subject matter of U.S. Pat. No. 3,433,412,whereby the same is incorporated into this application by reference.

Therefore, it can be seen that the control system 10 illustrated in FIG.1 can be completely packaged within the control system unit 260 from thedevices 63 and 71 to the pneumatically operated valve means 14 and 14 sothat the control system 10 can comprise only five replaceablecomponents, namely, housing means 35, control system unit 260, device63, device 71 and pneumatic pump 19.

The pneumatically operated electrical switch means 56 of the controlsystem unit 260 is best illustrated in FIG. 10 wherein the housing plate269A forming the well 265 has an opening 270 formed through the wall 266thereof and communicating with a slot means 271 between the housingplate 269A and the adjacent housing plate 269B whereby a terminal 272can project through the slot 271 to be external of the unit 260 and formthe switch blade contact means 54 previously described inside the wellmeans 265. The annular sidewall means 273 of the housing plate 269A thatsurrounds the well 14 265 is thickened at 274 to provide a terminal postmeans so that a reduced portion 275 thereof can project through anopening 276 in another terminal 277 as well as through an opening 278 ofthe switch blade 52 and be fastened thereto by having its end 279 turnedover in a fastening or riveting manner.

The surface 266 of the housing plate 269A of the unit 260 has an annularflange projection 280 around which the cupshaped diaphragm 59 is securedto cooperate with the surface 266 in defining the chamber 61 previouslydescribed which is adapted to be disposed in fluid communication with apassage 281 that forms part of the conduit means 106 previouslydescribed. The diaphragm 59 is formed with integral post means 282 thatpasses through suitable opening means 283 in the switch blade 52 so asto provide the tying means 60 previously described for controllingmovement of the switch blade 52 relative to the contact 54, the switchblade 52 having its contact means 53 disposed between the diaphragm 59and the post 274.

In this manner, when a vacuum source is interconnectedto the chamber 61,the diaphragm 59 is carried to the left in FIG. 10 and carries theswitch blade 52 therewith in opposition to the natural spring force ofthe switch blade 52 which tend to maintain the same in the positionillustrated in FIG. 10 (when the spring force of the blade 52 isutilized in place of the previously described compression spring 62) soas to place the contact 53 into electrical contact with the contact 54for the ignition purposes previously described. When the vacuum sourceis disconnected from the chamber 61 so that the chamber 61 can bereturned to atmospheric conditions in the manner previously described,the natural spring force of the spring blade 52 carries the diaphragm 59to the right in FIG. 10 to the position illustrated in FIG. 10 wherebyelectrical contact is broken between the contacts 53 and 54 asillustrated.

In order to provide for the controlled bleed means 108, and 100 of thecontrol system 10 previously described, the surface 263 of the controlunit 260 is interrupted by a large circular opening 284 in the mannerillustrated in FIG. 7 to define a flat, circular, recessed surface 285having the opening 100, 100 and 108 formed therein for communicating tothe atmosphere through the cutout or recess 255 in the housing 35 at thesurface 252 thereof with the circular opening 284 containing suitablefiltering material (not shown) to filter any air flow into the openings100, 100 and 108 for the purposes previously described.

Thus, it can be seen that the control system unit 260 of this inventioncan be readily utilized in combination with the housing means 35 for thepneumatically operated valve means 14 and 14' and can readily bereplaced therefrom for repair purposes b another such control systemunit 260 in a simple plugout, plug-in manner.

Therefore, it can be seen that this invention not only pro vides animproved packaging arrangement for a pneumatically operated controlsystem or the like, but also this invention provides improved parts forsuch a control system or the like.

While the form of the invention now preferred has been disclosed anddescribed as required by the statutes, other forms may be utilized allcoming within the scope of the claims which follow.

What is claimed is:

1. In combination, a housing means having inlet means and outlet meansseparated by valve seat means, pneumatically operated valve meanscarried by said housing means for opening and closing said valve seatmeans, and a pneumatically operated control system unit for operatingsaid pneumatically operated valve means and being detachable carried bysaid housing means.

2. A combination as set forth in claim 1 wherein said control systemunit has nipple conduit means for leading to said pneumatically operatedvalve means, said housing means having opening means leading to saidpneumatically operated valve means, said nipple conduit means of saidunit being detachable telescoped in said opening means of said housingmeans.

3. A combination as set forth in claim 2 wherein said pneumaticallyoperated valvemeans comprises a pair thereof disposed in series, saidopening means and said nipple conduit means also comprising pairsthereof respectively for said pair of pneumatically operated valvemeans.

4. A combination as set forth in claim 1 wherein said housing means hasa pocket means formed therein, said control system unit being detachabledisposed in said pocket means.

5. A combination as set forth in claim 4 wherein said housing meansincludes a removable cover means for partially closing saidpocket meansand for retaining said control system unit in said pocket means.

6. A combination as set forth in claim 1 wherein said control systemunit comprises a package of a plurality of housing plates securedtogether to hold control components of said system therebetween.

7. A combination as set forth in claim 6 wherein said housing plates aresonically welded together.

8. A combination as set forth in claim 6 wherein fluid passages areprovided in said control unit interconnecting certain control componentstogether.

9. A combination as set forth in claim 8 wherein one of said controlcomponents comprises a one-way check valve for one of said fluidpassages.

10. A combination as set forth in claim 8 wherein one of said controlcomponents comprises a pneumatically operated logic means.

11. A combination as set forth in claim 1 wherein said control systemunit has a pneumatically operated electrical switch means thereon.

12. A combination as set forth in claim 1 1 wherein said control systemunit has a well therein; said switch means being disposed in said wellto be protected thereby.

13. A combination as set forth in claim 12 wherein said switch means hasterminal means, said unit and said housing means cooperating together toexpose said terminal means for external electrical connection thereto.

14. A combination as set forth in claim 13 wherein said housing meansincludes a detachable cover member for opening and closing said well ofsaid unit.

15. A combination as set forth in claim 1 wherein said housing means haspocket means of substantially rectangular crosssectional configurationand said control unit has a substantially rectangular cross-sectionalconfiguration complementing said pocket means, said control unit beingdetachable disposed in said pocket means of said housing means.

16. A control system comprising a source of fuel, a burner means, apneumatic source, a housing means having inlet means and outlet meansseparated by valve seat means, means interconnecting said fuel source tosaid inlet means, means interconnecting said burner means to saidoutlet, pneumatically operated valve means carried by said housing meansfor opening and closing said valve seat means, and a pneumaticallyoperated control system unit for operating said pneumatically operatedvalve means and being detachable carried by said housing means, meansinterconnecting said pneumatic source to said control unit, said controlunit being adapted to interconnect said pneumatic source to saidpneumatically operated valve means to open the same.

17. A control system as set forth in claim 16 wherein said controlsystem unit has nipple conduit means for leading to said pneumaticallyoperated valve means, said housing means having opening means leading tosaid pneumatically operated valve means, said nipple conduit means ofsaid unit being detachable telescoped in said opening means of saidhousing means.

18. A control system as set forth in claim 17 wherein said pneumaticallyoperated valve means comprises a pair thereof disposed in series, saidopening means and said nipple conduit means also comprising pairsthereof respectively for said pair of pneumatically operated valvemeans.

19. A control system as set forth in claim 16 wherein said housing meanshas apocket means formed therein, said control system unit beingdetachable disposed in said pocket means.

20. A control system as set forth in claim 19 wherein said housing meansincludes a removable cover means for partially closing said pocket meansfor retaining said control system unit in said pocket means.

21. A control system as set forth in claim 16 wherein said controlsystem unit comprises a package of a plurality of housing plates securedtogether to hold control components of said system therebetween.

22. A control system as set forth in claim 21 wherein said housingplates are sonically welded together.

23. A control system as set forth in claim 21 wherein fluid passages areprovided in said control unit interconnecting certain control componentstogether.

24. A control system as set forth in claim 23 wherein one of saidcontrol components comprises a one-way check valve for one of said fluidpassages.

25. A control system as set forth in claim 23 wherein one of saidcontrol components comprises a pneumatically operated logic means.

26. A control system as set forth in claim 16 wherein said controlsystem unit has a pneumatically operated electrical switch meansthereon.

27. A control system as set forth in claim 26 wherein said controlsystem unit has a well therein, said switch means being disposed in saidwell to be protected there by.

28. A control system as set forth in claim 27 wherein said switch meanshas terminal means, said unit and said housing means cooperatingtogether to expose said terminal means for external electricalconnection thereto.

29. A control system as set forth in claim 28 wherein said housing meansincludes a detachable cover member for opening and closing said well ofsaid unit.

30. A control system as set forth in claim 16 wherein said housing meanshas pocket means of substantially rectangular cross-sectionalconfiguration and said control unit has a substantially rectangularcross sectional configuration complementing said pocket means, saidcontrol unit being detachable disposed in said pocket means of saidhousing means.

31. A control system unit for controlling a pneumatically operateddevice comprising a housing means having a surface interrupted by recessmeans to define a well therein, and a pneumatically operated electricalswitch means disposed in said well and being carried by said housingmeans, said housing means having passage means leading to saidpneumatically operated switch means for interconnecting a pneumaticsource thereto.

32. A control system unit as set forth in claim 31 wherein said housingmeans comprises a plurality of plastic plates sonically welded together.

33. A control system unit as set forth in claim 31 wherein at least onepneumatically operated control component means is carried by saidhousing means and is disposed between certain of said plates.

34. A control system unit as set forth in claim 33 wherein said controlcomponent means comprises a three diaphragm member.

35. A control system as set forth in claim 33 wherein said controlcomponent means comprises a check valve means.

36. A control system unit as set forth in claim 31 wherein saidelectrical switch means comprises a flexible diaphragm cooperating withsaid housing means to define a chamber therebetween, and a movableswitch blade carried by said housing means and being interconnected tosaid diaphragm to move in unison therewith.

37. A control system unit as set forth in claim 36 wherein a fixedswitch blade is carried by said housing means in a position to beengaged by said movable switch blade.

38. A control system unit as set forth in claim 37 wherein said housingmeans is formed from a plurality of plastic plates one of which definessaid well, one of said switch blades being secured to said one plate bya rivet connection therewith.

1. In combination, a housing means having inlet means and outlet meansseparated by valve seat means, pneumatically operated valve meanscarried by said housing means for opening and closing said valve seatmeans, and a pneumatically operated control system unit for operatingsaid pneumatically operated valve means and being detachable carried bysaid housing means.
 2. A combination as set forth in claim 1 whereinsaid control system unit has nipple conduit means for leading to saidpneumatically operated valve means, said housing means having openingmeans leading to said pneumatically operated valve means, said nippleconduit means of said unit being detachable telescoped in said openingmeans of said housing means.
 3. A combination as set forth in claim 2wherein said pneumatically operated valve means comprises a pair thereofdisposed in series, said opening means and said nipple conduit meansalso comprising pairs thereof respectively for said pair ofpneumatically operated valve means.
 4. A combination as set forth inclaim 1 wherein said housing means has a pocket means formed therein,said control system unit being detachable disposed in said pocket means.5. A combination as set forth in claim 4 wherein said housing meansincludes a removable cover means for partially closing said pocket meansand for retaining said control system unit in said pocket means.
 6. Acombination as set forth in claim 1 wherein said control system unitcomprises a package of a plurality of housing plates secured together tohold control components of said system therebetween.
 7. A combination asset forth in claim 6 wherein said housing plates are sonically weldedtogether.
 8. A combination as set forth in claim 6 wherein fluidpassages are provided in said control unit interconnecting certaincontrol components together.
 9. A combination as set forth in claim 8wherein one of said control components comprises a one-way check valvefor one of said fluid passages.
 10. A combination as set forth in claim8 wherein one of said control components comprises a pneumaticallyoperated logic means.
 11. A combination as set forth in claim 1 whereinsaid control system unit has a pneumatically operated electrical switchmeans thereon.
 12. A combination as set forth in claim 11 wherein saidcontrol system unit has a well therein; said switch means being disposedin said well to be protected thereby.
 13. A combination as set forth inclaim 12 wherein said switch means has terminal means, said unit andsaid housing means cooperating together to expose said terminal meansfor external electrical connection thereto.
 14. A combination as setforth in claim 13 wherein said housing means includes a detachable covermember for opening and closing said well of said unit.
 15. A combinationas set forth in claim 1 wherein said housing means has pocket means ofsubstantially rectangular cross-sectional configuration and said controlunit has a substantially rectangular cross-sectional configurationcomplementing said pocket means, said control unit being detachabledisposed in said pocket means of said housing means.
 16. A controlsystem comprising a source of fuel, a burner means, a pneumatic source,a housing means having inlet means and outlet means separated by valveseat means, means interconnecting said fuel source to said inlet means,means interconnecting said burner means to said outlet, pneumaticallyoperated valve means carried by said housing means for opening andclosing said valve seat means, and a pneumatically operated controlsystem unit for operating said pneumatically operated valve means andbeing detachable carried by said housing means, means interconnectingsaid pneumatic source to said control unit, said control unit beingadapted to interconnect said pneumatic source to said pneumaticallyoperated valve means to open the same.
 17. A control system as set forthin claim 16 wherein said control system unit has nipple conduit meansfor leading to said pneumatically operated valve means, said housingmeans having opening means leading to said pneumatically operated valvemeans, said nipple conduit means of said unit being detachabletelescoped in said opening means of said housing means.
 18. A controlsystem as set forth in claim 17 wherein said pneumatically operatedvalve means comprises a pair thereof disposed in series, said openingmeans and said nipple conduit means also comprising pairs thereofrespectively for said pair of pneumatically operated valve means.
 19. Acontrol system as set forth in claim 16 wherein said housing means has apocket means formed therein, said control system unit being detachabledisposed in said pocket means.
 20. A control system as set forth inclaim 19 wherein said housing means includes a removable cover means forpartially closing said pocket means for retaining said control systemunit in said pocket means.
 21. A control system as set forth in claim 16wherein said control system unit comprises a package of a plurality ofhousing plates secured together to hold control components of saidsystem therebetween.
 22. A control system as set forth in claim 21wherein said housing plates are sonically welded together.
 23. A controlsystem as set forth in claim 21 wherein fluid passages are provided insaid control unit interconnecting certain control components together.24. A control system as set forth in claim 23 wherein one of saidcontrol components comprises a one-way check valve for one of said fluidpassages.
 25. A control system as set forth in claim 23 wherein one ofsaid control components comprises a pneumatically operated logic means.26. A control system as set forth in claim 16 wherein said controlsystem unit has a pneumatically operated electrical switch meansthereon.
 27. A control system as set forth in claim 26 wherein saidcontrol system unit has a well therein, said switch means being disposedin said well to be protected there by.
 28. A control system as set forthin claim 27 wherein said switch means has terminal means, said unit andsaid housing means cooperating together to expose said terminal meansfor external electrical connection thereto.
 29. A control system as setforth in claim 28 wherein said housing means includes a detachable covermember for opening and closing said well of said unit.
 30. A controlsystem as set forth in claim 16 wherein said housing means has pocketmeans of substantially rectangular cross-sectional configuration andsaid control unit has a substantially rectangular cross-sectionalconfiguration complementing said pocket means, said control unit beingdetachable disposed in said pocket means of said housing means.
 31. Acontrol system unit for controlling a pneumatically operated devicecomprising a housing means having a surface interrupted by recess meansto define a well therein, and a pneumatically operated electrical switchmeans disposed in said well and being carried by said housing means,said housing means having passage means leading to said pneumaticallyoperated switch means for interconnecting a pneumatic source thereto.32. A control system unit as set forth in claim 31 wherein said housingmeans comprises a plurality of plastic plates sonically welded together.33. A control system unit as set forth in claim 31 wherein at least onepneumatically operated control component means is carried by saidhousing means and is disposed between certain of said plates.
 34. Acontrol system unit as set forth in claim 33 wherein said controlcomponent means comprises a three diaphragm member.
 35. A control systemas set forth in claim 33 wherein said control compOnent means comprisesa check valve means.
 36. A control system unit as set forth in claim 31wherein said electrical switch means comprises a flexible diaphragmcooperating with said housing means to define a chamber therebetween,and a movable switch blade carried by said housing means and beinginterconnected to said diaphragm to move in unison therewith.
 37. Acontrol system unit as set forth in claim 36 wherein a fixed switchblade is carried by said housing means in a position to be engaged bysaid movable switch blade.
 38. A control system unit as set forth inclaim 37 wherein said housing means is formed from a plurality ofplastic plates one of which defines said well, one of said switch bladesbeing secured to said one plate by a rivet connection therewith.
 39. Acontrol system as set forth in claim 38 wherein said plates aresonically welded together.
 40. A control system as set forth in claim 39wherein one of said switch blades has an end projecting out of saidhousing means between said one plate and the plate adjacent thereto toprovide a terminal means for that switch blade.